| Current Path : /sys/security/mac_bsdextended/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/security/mac_bsdextended/mac_bsdextended.c |
/*-
* Copyright (c) 1999-2002, 2007-2008 Robert N. M. Watson
* Copyright (c) 2001-2005 Networks Associates Technology, Inc.
* Copyright (c) 2005 Tom Rhodes
* Copyright (c) 2006 SPARTA, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
* It was later enhanced by Tom Rhodes for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: release/9.1.0/sys/security/mac_bsdextended/mac_bsdextended.c 192895 2009-05-27 14:11:23Z jamie $
*/
/*
* Developed by the TrustedBSD Project.
*
* "BSD Extended" MAC policy, allowing the administrator to impose mandatory
* firewall-like rules regarding users and file system objects.
*/
#include <sys/param.h>
#include <sys/acl.h>
#include <sys/kernel.h>
#include <sys/jail.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/stat.h>
#include <security/mac/mac_policy.h>
#include <security/mac_bsdextended/mac_bsdextended.h>
#include <security/mac_bsdextended/ugidfw_internal.h>
static struct mtx ugidfw_mtx;
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, bsdextended, CTLFLAG_RW, 0,
"TrustedBSD extended BSD MAC policy controls");
static int ugidfw_enabled = 1;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, enabled, CTLFLAG_RW,
&ugidfw_enabled, 0, "Enforce extended BSD policy");
TUNABLE_INT("security.mac.bsdextended.enabled", &ugidfw_enabled);
MALLOC_DEFINE(M_MACBSDEXTENDED, "mac_bsdextended", "BSD Extended MAC rule");
#define MAC_BSDEXTENDED_MAXRULES 250
static struct mac_bsdextended_rule *rules[MAC_BSDEXTENDED_MAXRULES];
static int rule_count = 0;
static int rule_slots = 0;
static int rule_version = MB_VERSION;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_count, CTLFLAG_RD,
&rule_count, 0, "Number of defined rules\n");
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_slots, CTLFLAG_RD,
&rule_slots, 0, "Number of used rule slots\n");
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_version, CTLFLAG_RD,
&rule_version, 0, "Version number for API\n");
/*
* This is just used for logging purposes, eventually we would like to log
* much more then failed requests.
*/
static int ugidfw_logging;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, logging, CTLFLAG_RW,
&ugidfw_logging, 0, "Log failed authorization requests");
/*
* This tunable is here for compatibility. It will allow the user to switch
* between the new mode (first rule matches) and the old functionality (all
* rules match).
*/
static int ugidfw_firstmatch_enabled;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, firstmatch_enabled,
CTLFLAG_RW, &ugidfw_firstmatch_enabled, 1,
"Disable/enable match first rule functionality");
static int
ugidfw_rule_valid(struct mac_bsdextended_rule *rule)
{
if ((rule->mbr_subject.mbs_flags | MBS_ALL_FLAGS) != MBS_ALL_FLAGS)
return (EINVAL);
if ((rule->mbr_subject.mbs_neg | MBS_ALL_FLAGS) != MBS_ALL_FLAGS)
return (EINVAL);
if ((rule->mbr_object.mbo_flags | MBO_ALL_FLAGS) != MBO_ALL_FLAGS)
return (EINVAL);
if ((rule->mbr_object.mbo_neg | MBO_ALL_FLAGS) != MBO_ALL_FLAGS)
return (EINVAL);
if ((rule->mbr_object.mbo_neg | MBO_TYPE_DEFINED) &&
(rule->mbr_object.mbo_type | MBO_ALL_TYPE) != MBO_ALL_TYPE)
return (EINVAL);
if ((rule->mbr_mode | MBI_ALLPERM) != MBI_ALLPERM)
return (EINVAL);
return (0);
}
static int
sysctl_rule(SYSCTL_HANDLER_ARGS)
{
struct mac_bsdextended_rule temprule, *ruleptr;
u_int namelen;
int error, index, *name;
error = 0;
name = (int *)arg1;
namelen = arg2;
if (namelen != 1)
return (EINVAL);
index = name[0];
if (index >= MAC_BSDEXTENDED_MAXRULES)
return (ENOENT);
ruleptr = NULL;
if (req->newptr && req->newlen != 0) {
error = SYSCTL_IN(req, &temprule, sizeof(temprule));
if (error)
return (error);
ruleptr = malloc(sizeof(*ruleptr), M_MACBSDEXTENDED,
M_WAITOK | M_ZERO);
}
mtx_lock(&ugidfw_mtx);
if (req->oldptr) {
if (index < 0 || index > rule_slots + 1) {
error = ENOENT;
goto out;
}
if (rules[index] == NULL) {
error = ENOENT;
goto out;
}
temprule = *rules[index];
}
if (req->newptr && req->newlen == 0) {
KASSERT(ruleptr == NULL, ("sysctl_rule: ruleptr != NULL"));
ruleptr = rules[index];
if (ruleptr == NULL) {
error = ENOENT;
goto out;
}
rule_count--;
rules[index] = NULL;
} else if (req->newptr) {
error = ugidfw_rule_valid(&temprule);
if (error)
goto out;
if (rules[index] == NULL) {
*ruleptr = temprule;
rules[index] = ruleptr;
ruleptr = NULL;
if (index + 1 > rule_slots)
rule_slots = index + 1;
rule_count++;
} else
*rules[index] = temprule;
}
out:
mtx_unlock(&ugidfw_mtx);
if (ruleptr != NULL)
free(ruleptr, M_MACBSDEXTENDED);
if (req->oldptr && error == 0)
error = SYSCTL_OUT(req, &temprule, sizeof(temprule));
return (error);
}
SYSCTL_NODE(_security_mac_bsdextended, OID_AUTO, rules,
CTLFLAG_MPSAFE | CTLFLAG_RW, sysctl_rule, "BSD extended MAC rules");
static void
ugidfw_init(struct mac_policy_conf *mpc)
{
mtx_init(&ugidfw_mtx, "mac_bsdextended lock", NULL, MTX_DEF);
}
static void
ugidfw_destroy(struct mac_policy_conf *mpc)
{
int i;
for (i = 0; i < MAC_BSDEXTENDED_MAXRULES; i++) {
if (rules[i] != NULL)
free(rules[i], M_MACBSDEXTENDED);
}
mtx_destroy(&ugidfw_mtx);
}
static int
ugidfw_rulecheck(struct mac_bsdextended_rule *rule,
struct ucred *cred, struct vnode *vp, struct vattr *vap, int acc_mode)
{
int mac_granted, match, priv_granted;
int i;
/*
* Is there a subject match?
*/
mtx_assert(&ugidfw_mtx, MA_OWNED);
if (rule->mbr_subject.mbs_flags & MBS_UID_DEFINED) {
match = ((cred->cr_uid <= rule->mbr_subject.mbs_uid_max &&
cred->cr_uid >= rule->mbr_subject.mbs_uid_min) ||
(cred->cr_ruid <= rule->mbr_subject.mbs_uid_max &&
cred->cr_ruid >= rule->mbr_subject.mbs_uid_min) ||
(cred->cr_svuid <= rule->mbr_subject.mbs_uid_max &&
cred->cr_svuid >= rule->mbr_subject.mbs_uid_min));
if (rule->mbr_subject.mbs_neg & MBS_UID_DEFINED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_subject.mbs_flags & MBS_GID_DEFINED) {
match = ((cred->cr_rgid <= rule->mbr_subject.mbs_gid_max &&
cred->cr_rgid >= rule->mbr_subject.mbs_gid_min) ||
(cred->cr_svgid <= rule->mbr_subject.mbs_gid_max &&
cred->cr_svgid >= rule->mbr_subject.mbs_gid_min));
if (!match) {
for (i = 0; i < cred->cr_ngroups; i++) {
if (cred->cr_groups[i]
<= rule->mbr_subject.mbs_gid_max &&
cred->cr_groups[i]
>= rule->mbr_subject.mbs_gid_min) {
match = 1;
break;
}
}
}
if (rule->mbr_subject.mbs_neg & MBS_GID_DEFINED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_subject.mbs_flags & MBS_PRISON_DEFINED) {
match =
(cred->cr_prison->pr_id == rule->mbr_subject.mbs_prison);
if (rule->mbr_subject.mbs_neg & MBS_PRISON_DEFINED)
match = !match;
if (!match)
return (0);
}
/*
* Is there an object match?
*/
if (rule->mbr_object.mbo_flags & MBO_UID_DEFINED) {
match = (vap->va_uid <= rule->mbr_object.mbo_uid_max &&
vap->va_uid >= rule->mbr_object.mbo_uid_min);
if (rule->mbr_object.mbo_neg & MBO_UID_DEFINED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_GID_DEFINED) {
match = (vap->va_gid <= rule->mbr_object.mbo_gid_max &&
vap->va_gid >= rule->mbr_object.mbo_gid_min);
if (rule->mbr_object.mbo_neg & MBO_GID_DEFINED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_FSID_DEFINED) {
match = (bcmp(&(vp->v_mount->mnt_stat.f_fsid),
&(rule->mbr_object.mbo_fsid),
sizeof(rule->mbr_object.mbo_fsid)) == 0);
if (rule->mbr_object.mbo_neg & MBO_FSID_DEFINED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_SUID) {
match = (vap->va_mode & S_ISUID);
if (rule->mbr_object.mbo_neg & MBO_SUID)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_SGID) {
match = (vap->va_mode & S_ISGID);
if (rule->mbr_object.mbo_neg & MBO_SGID)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_UID_SUBJECT) {
match = (vap->va_uid == cred->cr_uid ||
vap->va_uid == cred->cr_ruid ||
vap->va_uid == cred->cr_svuid);
if (rule->mbr_object.mbo_neg & MBO_UID_SUBJECT)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_GID_SUBJECT) {
match = (groupmember(vap->va_gid, cred) ||
vap->va_gid == cred->cr_rgid ||
vap->va_gid == cred->cr_svgid);
if (rule->mbr_object.mbo_neg & MBO_GID_SUBJECT)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbo_flags & MBO_TYPE_DEFINED) {
switch (vap->va_type) {
case VREG:
match = (rule->mbr_object.mbo_type & MBO_TYPE_REG);
break;
case VDIR:
match = (rule->mbr_object.mbo_type & MBO_TYPE_DIR);
break;
case VBLK:
match = (rule->mbr_object.mbo_type & MBO_TYPE_BLK);
break;
case VCHR:
match = (rule->mbr_object.mbo_type & MBO_TYPE_CHR);
break;
case VLNK:
match = (rule->mbr_object.mbo_type & MBO_TYPE_LNK);
break;
case VSOCK:
match = (rule->mbr_object.mbo_type & MBO_TYPE_SOCK);
break;
case VFIFO:
match = (rule->mbr_object.mbo_type & MBO_TYPE_FIFO);
break;
default:
match = 0;
}
if (rule->mbr_object.mbo_neg & MBO_TYPE_DEFINED)
match = !match;
if (!match)
return (0);
}
/*
* MBI_APPEND should not be here as it should get converted to
* MBI_WRITE.
*/
priv_granted = 0;
mac_granted = rule->mbr_mode;
if ((acc_mode & MBI_ADMIN) && (mac_granted & MBI_ADMIN) == 0 &&
priv_check_cred(cred, PRIV_VFS_ADMIN, 0) == 0)
priv_granted |= MBI_ADMIN;
if ((acc_mode & MBI_EXEC) && (mac_granted & MBI_EXEC) == 0 &&
priv_check_cred(cred, (vap->va_type == VDIR) ? PRIV_VFS_LOOKUP :
PRIV_VFS_EXEC, 0) == 0)
priv_granted |= MBI_EXEC;
if ((acc_mode & MBI_READ) && (mac_granted & MBI_READ) == 0 &&
priv_check_cred(cred, PRIV_VFS_READ, 0) == 0)
priv_granted |= MBI_READ;
if ((acc_mode & MBI_STAT) && (mac_granted & MBI_STAT) == 0 &&
priv_check_cred(cred, PRIV_VFS_STAT, 0) == 0)
priv_granted |= MBI_STAT;
if ((acc_mode & MBI_WRITE) && (mac_granted & MBI_WRITE) == 0 &&
priv_check_cred(cred, PRIV_VFS_WRITE, 0) == 0)
priv_granted |= MBI_WRITE;
/*
* Is the access permitted?
*/
if (((mac_granted | priv_granted) & acc_mode) != acc_mode) {
if (ugidfw_logging)
log(LOG_AUTHPRIV, "mac_bsdextended: %d:%d request %d"
" on %d:%d failed. \n", cred->cr_ruid,
cred->cr_rgid, acc_mode, vap->va_uid,
vap->va_gid);
return (EACCES);
}
/*
* If the rule matched, permits access, and first match is enabled,
* return success.
*/
if (ugidfw_firstmatch_enabled)
return (EJUSTRETURN);
else
return (0);
}
int
ugidfw_check(struct ucred *cred, struct vnode *vp, struct vattr *vap,
int acc_mode)
{
int error, i;
/*
* Since we do not separately handle append, map append to write.
*/
if (acc_mode & MBI_APPEND) {
acc_mode &= ~MBI_APPEND;
acc_mode |= MBI_WRITE;
}
mtx_lock(&ugidfw_mtx);
for (i = 0; i < rule_slots; i++) {
if (rules[i] == NULL)
continue;
error = ugidfw_rulecheck(rules[i], cred,
vp, vap, acc_mode);
if (error == EJUSTRETURN)
break;
if (error) {
mtx_unlock(&ugidfw_mtx);
return (error);
}
}
mtx_unlock(&ugidfw_mtx);
return (0);
}
int
ugidfw_check_vp(struct ucred *cred, struct vnode *vp, int acc_mode)
{
int error;
struct vattr vap;
if (!ugidfw_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred);
if (error)
return (error);
return (ugidfw_check(cred, vp, &vap, acc_mode));
}
int
ugidfw_accmode2mbi(accmode_t accmode)
{
int mbi;
mbi = 0;
if (accmode & VEXEC)
mbi |= MBI_EXEC;
if (accmode & VWRITE)
mbi |= MBI_WRITE;
if (accmode & VREAD)
mbi |= MBI_READ;
if (accmode & VADMIN_PERMS)
mbi |= MBI_ADMIN;
if (accmode & VSTAT_PERMS)
mbi |= MBI_STAT;
if (accmode & VAPPEND)
mbi |= MBI_APPEND;
return (mbi);
}
static struct mac_policy_ops ugidfw_ops =
{
.mpo_destroy = ugidfw_destroy,
.mpo_init = ugidfw_init,
.mpo_system_check_acct = ugidfw_system_check_acct,
.mpo_system_check_auditctl = ugidfw_system_check_auditctl,
.mpo_system_check_swapon = ugidfw_system_check_swapon,
.mpo_vnode_check_access = ugidfw_vnode_check_access,
.mpo_vnode_check_chdir = ugidfw_vnode_check_chdir,
.mpo_vnode_check_chroot = ugidfw_vnode_check_chroot,
.mpo_vnode_check_create = ugidfw_check_create_vnode,
.mpo_vnode_check_deleteacl = ugidfw_vnode_check_deleteacl,
.mpo_vnode_check_deleteextattr = ugidfw_vnode_check_deleteextattr,
.mpo_vnode_check_exec = ugidfw_vnode_check_exec,
.mpo_vnode_check_getacl = ugidfw_vnode_check_getacl,
.mpo_vnode_check_getextattr = ugidfw_vnode_check_getextattr,
.mpo_vnode_check_link = ugidfw_vnode_check_link,
.mpo_vnode_check_listextattr = ugidfw_vnode_check_listextattr,
.mpo_vnode_check_lookup = ugidfw_vnode_check_lookup,
.mpo_vnode_check_open = ugidfw_vnode_check_open,
.mpo_vnode_check_readdir = ugidfw_vnode_check_readdir,
.mpo_vnode_check_readlink = ugidfw_vnode_check_readdlink,
.mpo_vnode_check_rename_from = ugidfw_vnode_check_rename_from,
.mpo_vnode_check_rename_to = ugidfw_vnode_check_rename_to,
.mpo_vnode_check_revoke = ugidfw_vnode_check_revoke,
.mpo_vnode_check_setacl = ugidfw_check_setacl_vnode,
.mpo_vnode_check_setextattr = ugidfw_vnode_check_setextattr,
.mpo_vnode_check_setflags = ugidfw_vnode_check_setflags,
.mpo_vnode_check_setmode = ugidfw_vnode_check_setmode,
.mpo_vnode_check_setowner = ugidfw_vnode_check_setowner,
.mpo_vnode_check_setutimes = ugidfw_vnode_check_setutimes,
.mpo_vnode_check_stat = ugidfw_vnode_check_stat,
.mpo_vnode_check_unlink = ugidfw_vnode_check_unlink,
};
MAC_POLICY_SET(&ugidfw_ops, mac_bsdextended, "TrustedBSD MAC/BSD Extended",
MPC_LOADTIME_FLAG_UNLOADOK, NULL);